The effects of fenoxycarb in a chronic Oomen feeding test – results of a ringtest

Background - The Oomen bee brood feeding test (Oomen et al. 1992)⁶ is recommended by the EFSA (2013)² as one method to investigate potential effects of plant protection products on honeybee brood (Apis mellifera L.), with the ‘brood termination rate’ as the key endpoint. In 2013 the test method of Oomen was adapted to a chronic feeding scenario including current methods (OECD GD 75, improvements by Pistorius et al. 2012⁷) and was subsequently ring-tested in 2013 and 2014.
Results - The results were compared to data of acute feeding studies. Overall the obtained results of the chronic Oomen feeding studies indicated that the design is a robust and reliable test method with low brood termination rates in the control and a sufficient exposure of the brood to the reference item.
Conclusion - Nevertheless, based on current experiences and recent publications adaptations are proposed concerning dosing of the test item, assessment intervals and methodology (digital brood assessments). Moreover the test method was compared to the bee brood test according to OECD GD 75 and several advantages were pointed out.